showing 36 of ~574560 from 574555 documents
Characterization and classification of different genotypes in a population of Cucumis melo based on their ability to regenerate shoots from leaf expl…
1995
Variability of the in vitro organogenic response from leaf explants of a seed population of Cueumis melo L. ev. Cantaloupe Charentais was analyzed to detect genotypic variability among individual seeds for shoot regeneration. Variation in shoot regeneration frequency among plants from different seeds was compared to that found among clonal replicas of each original plant. Clonal propagation was performed using in vitro culture of apical and axillary buds of axenic plants to avoid somaclonal variation. Results demonstrate the existence of highly significant differences among plants from the seed population. Regeneration frequency of leaf explants derived from clonally propagated sets of a si…
The new element 111
1995
The new element 111 was produced and unambiguously identified in an experiment at SHIP, GSI Darmstadt. Three nuclei of the isotope272111 were observed in irradiations of209Bi targets with64Ni projectiles of 318 MeV and 320 MeV energy. The cross-sections are (1.7 −1.4 +3.3 ) pb and (3.5 −2.3 +4.6 ) pb, respectively. The nuclei decay by a emission into the new and so far the heaviest isotopes of the elements 109 and 107 with mass numbers A=268 and A=264. Theα-decay chains were followed down to the known nuclei260105 and256Lr.
Pre- and Post-translational Regulation of Lysyl Oxidase by Transforming Growth Factor-β1 in Osteoblastic MC3T3-E1 Cells
1995
The final enzymatic step required for collagen cross-linking is the extracellular oxidative deamination of peptidyl-lysine and -hydroxylysine residues by lysyl oxidase. A cross-linked collagenous extracellular matrix is required for bone formation. The goals of this study were to compare the transforming growth factor (TGF)-beta 1 regulation of lysyl oxidase enzyme activity and steady state mRNA levels to changes in COL1A1 mRNA levels in MC3T3-E1 osteoblastic cells. TGF-beta 1 increased steady state lysyl oxidase and COL1A1 mRNA levels in a dose- and time-dependent manner. The increase in lysyl oxidase mRNA levels was transient, peaking at 12 h and 8.8 times controls in cells treated with 4…
The debye-waller factor in spincrossover molecular crystals: a mössbauer study on [FexZn1−x(ptz)6](BF4)2
1995
In a first approximation the Debye-Waller factor (DWF) of molecular crystals is factorized into a molecular and a lattice part:f=f m f l. In the case of spincrossover compounds there is the unique possibility to measure differences of both parts in the two spin states by switching the spin states with the LIESST effect. Measurements of the DWF depending on temperature, γ-ray direction and spin state were performed with57Fe-Mossbauer spectroscopy on three single crystals (R¯3) of the spincrossover system [FexZn1−x(ptz)6](BF4)2 (ptz=1-propyltetrazole), a concentrated sample withx=1 and diluted ones withx=0.30 andx=0.005. The DWF decreases from 10 to 300 K by a factor of ∼ 100 and its anisotro…
Behavioural responsiveness to picrotoxin and desipramine in adult rats prenatally exposed to different benzodiazepine receptor agonists
1995
The behavioural responsiveness to picrotoxin and desipramine was investigated in adult rats prenatally exposed to different benzodiazepine receptor agonists such as diazepam, alprazolam and zolpidem. Prenatal exposure to diazepam and alprazolam similarly potentiated the anti-immobility effect on the forced swimming test and the inhibitory effect on spontaneous motor activity of picrotoxin and desipramine and increased the seizure sensitivity to picrotoxin. Prenatal zolpidem seems to be ineffective. These data suggest that, despite the differences in their pharmacodynamic profile, prenatal exposure to diazepam and alprazolam, but not zolpidem, may have similar permanent consequences on the b…
Pancreatic enzyme therapy in childhood celiac disease. A double-blind prospective randomized study.
1995
The validity of pancreatic enzyme substitution therapy in the two months following diagnosis of celiac disease was investigated. Twenty patients (8 males, 12 females), mean age 14.2 months (group A) received an enzyme substitution preparation. The control group (group B) included 20 patients (9 males, 11 females), mean age 14.5 months, treated with placebo. Before starting treatment, we performed a stratification for age, weight-for-age at diagnosis, and degree of pancreatic insufficiency. The therapies were then administered randomly in double-blind fashion. On diagnosis and 30 and 60 days after commencement of a gluten-free diet with identical calorie intake in both groups, a series of an…
The energy calibration of LEP in the 1993 scan
1995
This report summarizes the procedure for providing the absolute energy calibration of the LEP beams during the energy scan in 1993. The average beam energy around the LEP ring was measured in 25 calibrations with the resonant depolarization technique. The time variation of this average beam energy is well described by a model of the accelerator based on monitored quantities. The absolute calibration of the centre of mass energies of the off-peak points is determined with a precision of 2 parts in 10(5) resulting in a systematic error on the Z-mass of about 1.4 MeV and on the Z-width of about 1.5 MeV.
Assessing the quality of the sampling of fuel peat using computer simulation
1995
A simulation scheme to assess and improve the performance of the sampling of fuel peat is considered. The scheme provides a practical possibility to inspect all possible sources of variation and error. Test results from a district heating plant are reported.
Notes on the historical vocabulary of neuroanatomy
1995
Surface and thin film analysis: an introductory survey
1995
Production and decay of269110
1995
In an experiment carried out to identify element 110, we have observed anα-decay chain, that can be unambiguously assigned to269110. In a scries of preexperiments the excitation functions of the fusion reactions50Ti +208Pb→258104* and58Fe +208Pb→266108* were measured with high precision in order to get the optimum projectile energies for the production of these heavy elements. The cross-section maxima of the 1n evaporation channels were observed at excitation energies of 15.6 MeV and 13.4 MeV, respectively. These data result in an optimum excitation energy of 12.3 MeV of the compound nucleus for the production of269110 in the reaction62Ni +208Pb→269110 + 1n. In irradiations at the correspon…
Autoimmune endocrine ophthalmopathy and retrobulbar antigens.
1995
Endocrine Ophthalmopathy (EO) is based on autoimmune processes that lead to lymphocyte infiltration of the retrobulbar space. In this study, antigenic character of retrobulbar adipose, connective and muscle tissue as well as of cultured fibroblasts and myoblasts were examined. Samples were obtained from EO patients (n = 13, 8 fem., age 26-82 years, median 47 years) undergoing orbital decompression surgery. Retrobulbar and abdominal tissue from 7 controls (4 fem., 48 - 74 y) was investigated, too. Tissues were homogenized and the proteins were separated by SDS-PAGE according to molecular weight. In order to recover the separated proteins in soluble form, an electroelution technique was emplo…
Les apports du modèle de recherches d'expériences à l'analyse du comportement dans le domaine culturel Une exploration conceptuelle et méthodologique
1995
International audience; Le modèle de recherche d'expériences de Holbrook et Hirschman a été présenté par ses auteurs comme un cadre conceptuel bien adapté à l'analyse des comportements dans le domaine culturel. Cette recherche analyse la capacité de variables explicatives des différences interindividuelles retenues par ce modèle à expliquer des différences dans les évocations affectives du théâtre par le public. La méthodologie mise en œuvre s'appuie sur l'analyse statistique de données textuelles recueillies auprès des différents segments de spectateurs.
Capillary Hysteresis in Nanopores: Theoretical and Experimental Studies of Nitrogen Adsorption on MCM-41
1995
Capillary hysteresis in cylindrical nanopores has been studied using MCM-41 as the prime example of a mesoporous material. These materials, due to their regular pore structure, can be considered to be candidates for reference adsorbents for standardizing adsorption measurements and methods for characterization of porous solids. They provide a unique opportunity for verification of theoretical models employed for predicting phase equilibrium in confined geometry. Three samples with monodisperse pore channels have been synthesized and examined using X-ray diffraction (XRD). Nitrogen adsorption isotherms were modeled using nonlocal density functional theory (NLDFT) in a wide range of pore size…
Intracytoplasmic Testicular Sperm Injection: An Effective Treatment for Otherwise Intractable Obstructive Azoospermia
1995
AbstractPurpose: We evaluated the efficacy of intracytoplasmic sperm injection with testicular spermatozoa.Materials and Methods: Intracytoplasmic sperm injection was performed with spermatozoa obtained from testicular biopsy specimens in 15 patients with obstructive azoospermia, in whom standard microsurgical procedures were not feasible or had previously failed.Results: Fertilization was achieved in 14 to 15 cycles. Mean fertilization rate per cycle was 63.6 percent. Four clinical pregnancies occurred, for a pregnancy rate of 26.7 percent per started cycle and 28.6 percent per transfer.Conclusions: Intracytoplasmic testicular sperm injection is followed by high fertilization rates, and of…
L'enseignement des langues à l'école élémentaire
1995
International audience; Ce rapport est basé sur une enquête longitudinale qui a consisté à suivre pendant deux ans un échantillon de 1500 élèves entrant au collège. Certains de ces élèves avaient bénéficié d'un enseignement de l'anglais à l'école primaire dans le cadre d'une expérimentation mise en place par le ministère de l'Éducation nationale, d'autres débutaient cet apprentissage au collège. Le dispositif d'évaluation mis en place a permis de conduire deux types d'analyses. D'une part, on a décrit l'effet d'un certain nombre de facteurs qui déterminent le niveau atteint en anglais par les élèves aux différentes étapes de la scolarité. D'autre part, on a mesuré l'impact de l'expérimentat…
Determination of Kinetic and Thermochemical Parameters of a Substitution Reaction at a Square-Planar Palladium(II) Complex in Water/AOT/n-Heptane Mic…
1995
Abstract The substitution reaction [Pd(bipy)(en)] 2+ + en → [Pd(en) 2 ] 2+ + bipy (where bipy = 2,2′-bipyridine and en = ethylenediamine) has been studied in water and water/AOT/ n -heptane microemulsions at various values of the molar ratio R ( R = [water]/[AOT]) by flow microcalorimetry. From calorimetric data, molar enthalpies of reaction and rate constants were obtained. These quantities indicate that, by increasing R , the reaction becomes less exothermic and its rate constant decreases, trending to the value observed in water. These features can be reasonably rationalized in terms of the peculiar solvation state of reactants inside the AOT reversed micelles and/or the peculiar physico…
Fatal venous air embolism: proof and volumetry by helical CT
1995
Electrical stimulation and swimming performance
1995
The purpose of the study was to examine the influence of a 3-wk period of electrostimulation training on the strength of the latissimus dorsi m. and the swimming performances of 14 competitive swimmers divided into 7 electrostimulated (EG) and 7 control swimmers (CG). The peak torques registered during the flexion-extension of the arm was determined with the help of an isokinetic dynamometer at different velocities (from -60 degrees.s(-1) to 360 degrees.s(-1)). Performances were measured over a 25-m pull buoy and a 50-m freestyle swim. For EG, a significant increase of the peak torques was measured in isometric, eccentric, and concentric conditions (P < 0.5). The swimming times declined sig…
Characterization of 5-hydroxytryptamine release from isolated rabbit and rat trachea: the role of neuroendocrine epithelial cells and mast cells
1995
Rabbit or rat isolated tracheae were incubated in vitro, and the release of 5-hydroxytryptamine (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) was determined by HPLC with electrochemical detection. Release of 5-HT from rabbit tracheae could be evoked by the calcium ionophore A 23187 and, in a calcium-dependent manner, by depolarizing concentrations of potassium (45 mmol/l), but not by the mast cell degranulating drug compound 48/80. High potassium- and A 23187-evoked release of 5-HT was markedly higher from tracheae of newborn compared to adult rabbits. In rabbit tracheae, mechanical removal of the mucosa resulted in 80-90% reduction in tissue 5-HT and in a similar reduction …
Effective diffusion coefficient and diffusion-controlled reactions in insulating solids with defects
1995
Abstract The expressions for effective diffusion coefficient are obtained in the mean field approximation for two-phase system for spatial dimensions of 1, 2 and 3. The existence of potential barrier for diffusion on the phase boundary was taken into account via the boundary conditions. Obtained formulae could be applied in the theory of diffusion-controlled reactions and for interpreting the experimental data on defect diffusion in two-phase media.
A comparative study of mortality in agricultural and industrial areas in Spain.
1995
The three main causes of contamination in the industrialized world are energy production, and industrial and agricultural activities. The aim of the present study was to examine changes in cause of death in order to contrast causes of death between agricultural and industrial areas. To this effect we have selected four zones — two predominantly industrial and two mainly agricultural — within the Valencian Community. Mortality figures were gathered corresponding to the same period 1976–1989, published by the Conselleria de Sanitat i Consum of the Generalitat Valenciana (Valencian Community health authorities). Thirty large groups of causes of death were established for posterior analysis. Mo…
Quantum repulsive Nonlinear Schrödinger models and their ‘Superconductivity’
1995
Abstract The fundamental role played by the quantum repulsive Nonlinear Schrodinger (NLS) equation in the evolution of our understanding of the phenomenon of superconductivity in appropriate metals at very low temperatures is surveyed. The first major work was that in 1947 by N. N. Bogoliubov, who studied the very physical 3-space-dimensions problem and super fluidity; and the survey takes the form of an actual dedication to that outstanding scientist who died four years ago. The 3-space-dimensions NLS equation is not integrable either classically or quantum mechanically. But a number of recently discovered closely related lattices in one space dimension (one space plus one time dimension) …
Killer-toxin-resistant kre12 mutants of Saccharomyces cerevisiae: genetic and biochemical evidence for a secondary K1 membrane receptor.
1995
The Saccharomyces cerevisiae killer toxin K1 is a secreted alpha/beta-heterodimeric protein toxin that kills sensitive yeast cells in a receptor-mediated two-stage process. The first step involves toxin binding to beta-1,6-D-glucan-components of the outer yeast cell surface; this step is blocked in yeast mutants bearing nuclear mutations in any of the KRE genes whose products are involved in synthesis and/or assembly of cell wall beta-D-glucans. After binding to the yeast cell wall, the killer toxin is transferred to the cytoplasmic membrane, subsequently leading to cell death by forming lethal ion channels. In an attempt to identify a secondary K1 toxin receptor at the plasma membrane leve…
Sediment delivery processes at basin scale
1995
Abstract Since eroded sediments are produced from different sources distributed throughout a basin, sediment delivery processes at basin scale have to be modelled by a spatially distributed approach. In this paper a new theoretically based relationship is proposed for evaluating the sediment delivery ratio, SDRi, of each morphological unit, i, into which a basin is divided. Then, using the sediment balance equation written for the basin outlet, a relationship between the basin sediment delivery ratio, SDRW and the SDRi is deduced. This relationship is shown to be independent of the soil erosion model used. Finally, a morphological criterion for estimating a coefficient, β, is proposed.
An electrochemical quartz crystal microbalance study of lithium insertion into thin films of tungsten trioxide I. Modeling of the ionic insertion mec…
1995
A theoretical description of the mechanism of lithium insertion into amorphous thin films of tungsten trioxide (a-WO3) prepared by thermal vacuum evaporation of WO3 powder is presented. The model developed is based on the experimental results obtained by chronoamperometry and ac impedance spectroscopy associated with electrochemical quartz crystal microbalance (EQCM). The electrode mass change and the current flowing through the electrochemical cell during cathodic polarization are simulta neously recorded. As expected, it can be observed that the insertion process is associated with a gain of mass of the inserted electrode at long times (t > 1 s). On the other hand at short times (t < 1 s)…
Graded Poisson structures on the algebra of differential forms
1995
We study the graded Poisson structures defined on Ω(M), the graded algebra of differential forms on a smooth manifoldM, such that the exterior derivative is a Poisson derivation. We show that they are the odd Poisson structures previously studied by Koszul, that arise from Poisson structures onM. Analogously, we characterize all the graded symplectic forms on ΩM) for which the exterior derivative is a Hamiltomian graded vector field. Finally, we determine the topological obstructions to the possibility of obtaining all odd symplectic forms with this property as the image by the pullback of an automorphism of Ω(M) of a graded symplectic form of degree 1 with respect to which the exterior der…
Clearance and metabolism of arachidonic acid by C6 glioma cells and astrocytes.
1995
Effects of increased levels of arachidonic acid (AA) were analyzed in vitro by employment of C6 glioma cells and astrocytes from primary culture. The cells were suspended in a physiological medium added with arachidonic acid (AA) in a concentration range from 0.01 to 0.5 mM. The concentration profiles of the fatty acid and AA-metabolites were subsequently followed for 90 min. AA was measured by gas chromatography, whereas the AA-metabolites PGF2 alpha and LTB4 by radioimmunoassay (RIA). Following administration of AA at 0.05 or 0.1 mM the medium was completely cleared from the fatty acid within 10 to 15 min. However, when 0.5 mM were added, AA concentrations of 0.36 +/- 0.055 mM were found …
Behçet's disease and coeliac disease
1995
Structural Investigation of Water/Lecithin/Cyclohexane Microemulsions by FT-IR Spectroscopy
1995
Abstract FT-IR spectra of water/lecithin/deuterated cyclohexane microemulsions as a function of water/lecithin molar ratio R ( R = [water]/[lecithin]) at various volume fractions ( O ) of the micellar phase have been recorded at 25°C. After elimination of the small spectral contributions due to deuterated cyclohexane and normalization, the shape of the C–H stretching band due to lecithin has been found dependent upon R and O whereas that of the O–H stretching band has been found dependent only upon R . The change in shape of the C–H band was interpreted in terms of a modification of the lecithin alkyl chain packing order. The analysis of the O–H band provides evidence that the hydroxylic gr…
The relation between theory and application in statistics
1995
General comments on the relation between theory and application in statistics are made and emphasis placed on issues and principles of model formulation. Three examples are described in outline. Criteria for the choice of models are discussed.
Difficulties in mobility among elderly people and their association with socioeconomic factors, dwelling environment and use of services.
1995
The purpose of this study was to clarify the extent to which elderly people have difficulties in mobility, and determine their association with socioeconomic factors, dwelling environment and use of services. The study groups were composed of two random samples of 800 persons aged 65–74 and 75–84, respectively. In all, 1224 non- institutionalized persons (80%) were interviewed at home. The respondents were asked to assess their ability to get about the house, negotiate stairs and walk outdoors, as well as manage certain physical exercise tasks. Difficulties in getting about outdoors were found most frequently among the women in the older age group (52% reported difficulties), and least freq…
Screening of tropical medicinal plants for antiinflammatory activity
1995
The antiinflammatory activity of different extracts from 16 tropical plant species belonging to 15 different families has been determined. They were administered topically on TPA-induced mouse ear oedema and orally on carrageenan-induced mouse paw oedema. In the latter, extracts from Diospyros leucomelas, Erythrospermum monticolumn, Ficus polita, Heteromorpha trifoliata, Hypericum lalandii, Kirkia acuminata, Pterocarpus angolensis and Zanha africana significantly reduced the oedema 3 h after carrageenan injection. All the extracts were considerably active when assayed topically with only three exceptions.
El pulmón y los viajes en avión
1995
Anti-Inflammatory Activity of Flavonol Glycosides fromErythrospermum monticolumDepending on Single or Repeated Local TPA Administration
1995
Two anti-inflammatory principles were isolated from the methanol extract of the leaves of Erythrospermum monticolum (Flacourtiaceae). The isolation was based on a guided bioassay of the inhibitory activity on TPA-induced ear edema in mice. These compounds were identified as quercetin 3-O-xylosyl(1-->2) rhamnoside and quercetin 3-O-rhamnoside. In addition, their effects on a chronic topic inflammation model were evaluated.
The effects of self-efficacy on computer usage
1995
Abstract This paper examines the effect of self-efficacy, belief in one's capabilities of using a computer in the accomplishment of specific tasks, on computer usage. It introduces an extended technology acceptance model (TAM) that explicitly incorporates self-efficacy and its determinants (experience and organizational support) as factors affecting computer anxiety, perceived ease of use, perceived usefulness and the use of computer technology. A survey of 450 microcomputer users in Finland found strong support for the conceptual model. In accordance with TAM, perceived usefulness had a strong direct effect on usage, while perceived ease of use had indirect effect on usage through perceive…